Process of purifying petroleum products



Aug. 23 1927.

S. J. DICKEY ET AL PROCESS oF PURIFYING PETROLEUM PRODUCTS Filed April 19, 1924 kuk .NPK

NNN N Patented- Aug. 23, 1927.

UNITED sTATEs PATENT OFFICE.

SAMUEL J'. DICKEY AND RAYMOND O. WHEELER, 0F LOS ANGELES, CALIFORNIA, AS- SIGNORS TO GENERAL PETROLEUM- CORPORATION OF CALIFORNIA, A CORPORA- TION F DELAWABE.

`:PROCESS OF PURIFYING PETROLEUM PRODUCTS.

Application iled. April 19, 1924. Serial No. 707,619.

`Our invention relates to the art of purifying mineral oils and particularly petroleum distillates. 'It may be readily applied to the treatment of gasoline and in the following specification we will describe' this application as illustrating the broad principles involved without, however, intending to limit ourselves to this particular application, as our invention is applicable to thetreatment of other distillates. 4

Gasoline, as now produced, often contains unsaturated compounds which are unstable and which are either objectionable due to imparting undesirable characteristics to the gasoline, or which break up into objectionable products. This is particularly true kof gasoline produced by many of the so-called cracking processes, much of which as originlly produced is objectionable in odor and co or.

It is an object of ourinvention to provide a process by which cracked gasoline can be treated to correct its undesirablecolor and odor and ,to produce a permanently water white and permanently uri-objectionable product.

With this and other objects in view, which will be made evident hereinafter,- we employ the apparatus shown in the attached drawing, whlch is a diagrammatic elevation partly 1n section.- Inf the apparat-us illus-- trated in this drawing 1 is a tank and 2'and r 3 are filters.A The oil to be treated is sup- ,plied under pressure, by any convenient means, such as a pump 13, to an inj ector4 '14. The injector 14 draws a reagent from the bottom of the tank 1 through a pipe 15. This reagent, when treating gasoline, may be a sulphuric acid sludge formed byI intro- 4`0 ducing sulphuric acid into the tank 1\ through a pipe 15. This acid is heavier than the oil and settles in the bottom of the tank 1, being delivered through the pipe 15 to the injector 14. In the injector, the oil under high velocity, due to a @constricted orifice and the pressure of the pump 13, is lmixed with the acid,\the mixing continuinog due to a turbulence of the mixture in a vertical mixing pipe 17. The pipe 17 dismarked color, usually a light pink. Contin- "the apparatus ceases to function properly.

charges the mixture into the upper part of' 50 the tank 1.

In the tank 1, the larger particles of acid settle immediately to the bottom, being mixed with the acid already present in the tank. The distillate, freed from the larger particles of acid, rises and passes through a pipe 18 into the lter'2. The pipe 18 is provided with a valve 19.

The tank 1 is of such size that there is good separation of heavy acid particles therein, and the distillate passing through the pipe 18 is apparently free from drops of acid. It shows an acid reaction, however, when' tested with litmus paper and has a G5 ued washing with water in a suitable apparatus, not shown, will greatly reduce the acidity of the distillate, but the objectionable pink color persists unless this washing is continued to a degree that is quite expensive. The pink color is probably due to mi; nute `particle/s of acid containing reaction products which give it its color.

'We have found j hat the acidity can be completely neutralized and a water white product producedfby subjecting the distillate, leaving the top lof the tank 1- through the pipe 18, to dry sand filtration. This can be economically accomplished in the filter 2, which consists of a' tight shell 20, having a' screen or grating 21 supporting a body of dry sand 22. The distillate is delivered through the pipe 18, -below the screen 21 and passes upwardly through the dry sand 22,A and through a pipe 23 having a valve 24, to suitable storage tanks not shown.

lThe distillate so .produced is water white and neutral. The small particles of acid sludge are caught in the dry sand 22 and the product is ahigh-grade colorless gasoline free from objectionable odors. Unfor-v tunately, however, the introduction of the acid sludge-particles into the" dry sand rapidly destroys the efficiency of this sand and We, therefore, provide the ilter 3 which is supplied with oil from the pipe 18 through a valve 31. As sopn as the filter 2 starts to clog up with acid sludge, We close the valve 19 and open the Valve 31, thus turning the distillate to be cleaned into the filter 3.

We then close the valve 24 and open a valve 25 in a pipe 26, leading to a suitable drain, not shown. l/Vater under pressure issupplied through a Valve 27, to a pipe 28 from a pump 29. The Water passes down- Wardly through the sand 22 and carries With it the greater portion of the acid sludge particles, which are discharged with the Water accomplish by forcing air from a blower 50 throu h a heating coil 51 and a valve 52 into the pipe 28 and through 'the sand 22. The coil 51 may be heated by a gas burner 53. This is preferably done While the sand is still hot from the steam treatment.

As soon as the sand 22 is thoroughly dried, the valves 27', 42, 52 and 25 may be closed, and the filter 2 put in service again by opening the valves 19 and 24. The filter 3,

" which is a duplicate of filter 2, may then-be cut out of service by closing the valve 31. The sand in the filter 3 may then be cleaned so that it is ready for service When the filter n2 needs cleaning.

It will be seen that our invention is noyel in that We are the first to disclose that gasoline can be purified by treatment With 'acid followed by dry sand filtration, all Waterl Washing being preferably omitted. Our process is, however, rendered practical by the use of dry sand as a filtering agent and by the use of the novel means used by us to clean and dry the sand at necessary intervals. 1We have illustrated certain preferred forms of 'apparatus and described our method of operation as applied-to the treatment of gasoline, but We do not Wish to be understood that We thereby restrict the scope of our invention which is defined by the annexed claims.

We claim-as our invention:

l. The steps in the production of a neutral petroleum distillate from an acid treated distillate, comprising: settling and removing the coarsesludge produced by the acid treatment, passing the acid distillate through a pack of dried sand retained in a substantially closed vessel for the removal of fine sludge particles, continuing such filtration until the sand pack ceases to function by becoming internally coated With sludge, discontinuing the filtration, draining the free oil from the vessel, Washing out the sludge with steam,and drying the sand by the passage therethrough of a current of air, thereby 4bringing said sand into condition for re-use Without removing the sand from its operating position in the vessel.,

2. The steps in the production of a neutral f petroleum distillate from an acid treated distillate, comprising: settling and remo-v-` land part of the sludge With Water,'Washing out the remainder of the sludge with steam, and drying the sand by the passage therethrough of a current of air, thereby bringing said sand into condition for re-use Without removing the sand from its operating position in the vessel.

8. The' steps in the continuous production of a neutral petroleum distillate from an acid treated distillate, comprising: settling and removing the coarse sludge produced by the acid treatment, passing the acid distillate through a pack of dried sand retained in a substantially closed vessel, for the removal of fine sludge particles, continuing such filtration until the sand pack ceases to function by becoming internally coated with' sludge, diverting the stream of acid distillate into a second similar pack so connected With the source of supply as to be capable of being used alternately With the first said pack, draining the oil from the first vessel, Washing the sludge from the first pack with steam, and drying such first pack by the passage therethrough of a -current of air thereby bringing the sand in said first pack into condition for re-use Without removing such sand from its operating position in the first vessel. 4. The steps in the continuous production of. a neutral petroleum distillate from an acid treated distillate, comprising: settling and removing the coarse sludge produced by the acid treatment, passing the acid distillate through a pack of dried sand retained in a substantially closed vessel, for theremoval of fine sludge particles, continuing such filtration until the sand pack ceases to function by becoming internally coated With sludge, diverting the stream of acid distillate into a second similar pack so connected With the source of supply as to be capable of being used alternately Withthe first said pack, draining the oil from the first vessel, Washing the oil and part of the sludge out of the first pack by the passage therethrough of a ow of Water, Washing the remainder ,of the'sludge out of the first pack by the through of n. current of heated air, thereby bringing the sand in said rst pack into condition for re-use Without removlng such sand from its operating position in the irst vessel.

In testimony whereof, We have hereunto 10 set our hands at Los Angeles, California, this 10th day of April, 1924.

SAMUEL J. DICKEY. RAYMOND C. WHEELER. 

